Preference Presets.

Not much of a needed feature, but rather a suggestion to further improve productivity and efficiency within Photoshop. The idea for preference presets would be so rather than having to go to photoshop's preferences to change, say, guides/rulers based on what's needed as an example. Have it so preferences can be instantly switched based on saved profiles that's defined the user. This can be additionally helpful in speeding up the process if the user can define a key shortcut to switch between each preset.

You could record PS preferences as action. And then show action panel in button mode. I used this for changing grid color and size. Only thing to consider is that in action will be probably only changed preferences. Not all Photoshop settings.